MerCruiser 7.4L 310HP Running Rough and throwing code 43 Continuous knock
03-07-2017, 02:57 PM
#11
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I have two knock sensor's if you need one, Im by the KS speedway, I had a 272 also back in the day 502 mag mpi, great boat
Edit: make sure its on TDC and the #1 plug wire is where the rotor is pointed at.
Edit: make sure its on TDC and the #1 plug wire is where the rotor is pointed at.
Last edited by F-2 Speedy; 03-07-2017 at 02:59 PM.
03-07-2017, 03:00 PM
#12
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Look at the harmonic balancer and find the degree markings. Take a white grease pencil and mark 8 BTDC.
Have the motor running until it's up to temp. Connect a timing light to plug wire number 1, which is front plug on port side. Connect positive and negative leads from timing light to battery post.
Insert the paper clip in pins A and B, then adjust rpms to 1800. Point timing light at balancer to see if 8 BTDC lines up with tab on timing chain cover. If it does your in time, if not, loosen distributor clamp slightly and rotate distributor until 8 lines up. Once lined up, tighten bolt on distributor clamp, and recheck timing.
Remove paper clip.
[ATTACH=CONFIG]565404[/ATTACH]
Have the motor running until it's up to temp. Connect a timing light to plug wire number 1, which is front plug on port side. Connect positive and negative leads from timing light to battery post.
Insert the paper clip in pins A and B, then adjust rpms to 1800. Point timing light at balancer to see if 8 BTDC lines up with tab on timing chain cover. If it does your in time, if not, loosen distributor clamp slightly and rotate distributor until 8 lines up. Once lined up, tighten bolt on distributor clamp, and recheck timing.
Remove paper clip.
[ATTACH=CONFIG]565404[/ATTACH]
03-07-2017, 03:48 PM
#13
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A loose coupler ( not properly torqued , wrong bolts,ect) can trip knock sensor. Once it takes enough timing out , you will see a dirty transom. Probably something simple , but something to check if you exhaust other ideas...Good Luck!!!
03-07-2017, 03:49 PM
#14
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Thanks!
03-07-2017, 04:34 PM
#15
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Look at the harmonic balancer and find the degree markings. Take a white grease pencil and mark 8 BTDC.
Have the motor running until it's up to temp. Connect a timing light to plug wire number 1, which is front plug on port side. Connect positive and negative leads from timing light to battery post.
Insert the paper clip in pins A and B, then adjust rpms to 1800. Point timing light at balancer to see if 8 BTDC lines up with tab on timing chain cover. If it does your in time, if not, loosen distributor clamp slightly and rotate distributor until 8 lines up. Once lined up, tighten bolt on distributor clamp, and recheck timing.
Remove paper clip.
[ATTACH=CONFIG]565404[/ATTACH]
Have the motor running until it's up to temp. Connect a timing light to plug wire number 1, which is front plug on port side. Connect positive and negative leads from timing light to battery post.
Insert the paper clip in pins A and B, then adjust rpms to 1800. Point timing light at balancer to see if 8 BTDC lines up with tab on timing chain cover. If it does your in time, if not, loosen distributor clamp slightly and rotate distributor until 8 lines up. Once lined up, tighten bolt on distributor clamp, and recheck timing.
Remove paper clip.
[ATTACH=CONFIG]565404[/ATTACH]
03-07-2017, 04:38 PM
#16
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Why in the world would you move to that God forsaken place, I use to live in the Colony when it had 5k people, now it has 55k
03-07-2017, 04:40 PM
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03-07-2017, 04:45 PM
#19
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If your single you moved to the right place..........if your married you moved to the wrong place...............LOL a buddy of mine is in Plano he has a 272 Boss, boats up on Texoma, he's a home grown boy so he talks funny
03-07-2017, 06:42 PM
#20
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Just a thought, buy a cheap mechanics stethoscope at parts store, listen at the head bolts and free rev the engine. If the engine really has something stimulating the knock sensor you will hear it. If it's from the rear of the engine you may need to run the engine with the outdrive off the boat to rule out drive noise. A lot of parts are turning in the outdrive even when the drive is in neutral.
